JP4645668B2 - Method for manufacturing ink jet recording head - Google Patents

Description

The present invention relates to the production how the ink jet recording head, in particular, unnecessary bonding between the substrates, a technique capable of preventing the blocked nozzle openings by adhesive.

  As shown in FIG. 10A, an ink jet recording head 200 according to a conventional example seals a piezoelectric element (that is, a piezo element) 201, a driver circuit 203 for driving the piezoelectric element, and the piezoelectric element. And a reservoir 207 that receives supply of ink liquid from the outside, a substrate 210 having a vibration plate 209 and a pressure generation chamber 211, and a nozzle plate 220 in which a nozzle opening 213 is formed. As shown in FIG. 10B, the ink jet recording head 200 having such a structure is formed by bonding each of the above portions with an adhesive and connecting the piezoelectric element 201 and the driver circuit 203 by wire bonding. Is assembled.

In recent years, the density of arrangement intervals of nozzle openings has been increased, and the connection between the piezoelectric element 201 and the driver circuit 203 by wire bonding is approaching the technical limit. In response to such a flow, a method of directly forming a driver circuit on the substrate or the sealing plate has been disclosed (for example, see Patent Documents 1 and 2). According to this method, since the connection between the piezoelectric element and the driver circuit is performed by forming a metal wiring by photolithography technology or by flip chip mounting, a finer connection than wire bonding is possible. For this reason, it can respond to the densification of the arrangement interval of a nozzle opening part.
JP 2001-205815 A JP 2001-162794 A

However, the methods disclosed in the above-mentioned Patent Documents 1 and 2 are methods on the premise that the substrates are bonded to each other. That is, since a plurality of substrates formed with elements formed and processed are bonded together, the process is complicated and it is difficult to reduce the cost.
Further, the substrates are bonded to each other with an adhesive, but this adhesive may protrude from the joint surface and block the nozzle opening. Such a possibility is considered to increase as the nozzle opening diameter decreases and the arrangement interval increases in density.
The present invention was made in view of such circumstances, bonding between the substrates is not required, manufacturing how the ink jet recording head capable of preventing the blocked nozzle openings by adhesive The purpose is to provide.

  [Invention 1 and 2] A method of manufacturing an ink jet recording head according to Invention 1 includes a reservoir that receives an external supply of ink liquid, a pressure generation chamber that communicates with the reservoir, and a nozzle opening that communicates with the pressure generation chamber. A method of forming a flow path forming film on one surface side of a substrate having an integrated circuit, a step of forming a groove in the flow path forming film, and the groove Filling the sacrificial film, forming a vibration film on the sacrificial film and the flow path forming film, forming a piezoelectric element on the vibration film, and removing the substrate from the other surface side. Etching until the sacrificial film is exposed to form the reservoir, removing the sacrificial film through the reservoir, and forming the nozzle opening in the flow path forming film. It is an feature.

Here, as the “sacrificial film”, it is preferable to use a film having a higher etching selectivity than the “flow path forming film” (that is, a film that is more easily etched than the flow path forming film). For example, when the flow path forming film is a silicon oxide (SiO ₂ ) film, an amorphous silicon (a-Si) film can be used as the sacrificial film. When the flow path forming film is an a-Si film, a SiO ₂ film can be used as the sacrificial film. Furthermore, when the flow path forming film is a polysilicon (Poly-Si) film, a SiO ₂ film or a silicon germanium (SiGe) film can be used as the sacrificial film. The SiO ₂ film as the sacrificial film may be a PSG (Phospho Silicate Glass) film having a relatively high etching rate.

  According to a second aspect of the present invention, there is provided an ink jet recording head comprising: a reservoir that receives an external supply of an ink liquid; a pressure generation chamber that communicates with the reservoir; and a nozzle opening that communicates with the pressure generation chamber. A method of manufacturing a head, the step of forming a first flow path forming film on one surface side of a substrate having an integrated circuit, and the region serving as a first communication path connecting the pressure generating chamber and the reservoir Forming a first groove part in each of the first flow path forming film and the first flow path forming film in a region serving as a second communication path connecting the pressure generating chamber and the nozzle opening; and Filling the first sacrificial film with the first flow path forming film, forming the second flow path forming film on the first sacrificial film, and the second flow in the region to be the pressure generating chamber. Forming the second groove in the path forming film A step of filling the second groove with a second sacrificial film, a step of forming a vibration film on the second sacrificial film and the second flow path forming film, and a step of forming a piezoelectric element on the vibration film Etching the substrate from the other surface side until the first sacrificial film is exposed to form the reservoir, and removing the first sacrificial film and the second sacrificial film through the reservoir. And a step of forming the nozzle opening in the second flow path forming film.

  According to the manufacturing method of the ink jet recording head of the first and second aspects, the ink jet recording head is manufactured by performing a semiconductor process (that is, a film forming process, a photolithography process, an etching process, etc.) on one substrate. Can be manufactured. Compared to the conventional example, since it is not necessary to bond a plurality of substrates, the process can be simplified and the cost can be reduced. Moreover, since the adhesive for bonding is unnecessary, there is no possibility that the nozzle opening is blocked by the adhesive. For this reason, the ink jet recording head can be manufactured at a low cost and with a high yield.

[Invention 3] The method for manufacturing an ink jet recording head according to Invention 3 is the method for manufacturing the ink jet recording head according to Invention 2, wherein the step of forming the nozzle opening includes the second flow in a region to be the nozzle opening. After the step of forming the second groove portion in the path forming film, the step of filling the second groove portion with the second sacrificial film, and the step of forming the reservoir, the second sacrificial film via the reservoir And a step of etching and removing.
According to such a method, the step of forming the pressure generating chamber and the step of forming the nozzle opening can be performed in parallel, which can contribute to a reduction in the number of steps.

[Invention 4] The method of manufacturing an ink jet recording head according to Invention 4 is the method of manufacturing an ink jet recording head according to any one of Inventions 1 to 3, wherein the integrated circuit is formed on one surface of the substrate. The refractory metal is used as the wiring material of the integrated circuit. Here, the “refractory metal” is, for example, tungsten (W), tungsten silicide (WSi ₂ ), titanium (Ti) or titanium silicide (TiSi ₂ ), gold (Au), iridium (Ir), molybdenum (Mo), etc. For example, it is a metal having a melting point of 1000 ° C. or higher.
According to such a method, for example, even when heat treatment at about 700 ° C. is performed when forming the piezoelectric element, it is possible to prevent occurrence of problems such as disconnection due to heat.
[Invention 5] An ink jet recording head manufacturing method according to an invention 5 includes the steps of forming an insulating protective film on the piezoelectric element in the ink jet recording head manufacturing method according to the inventions 1 to 4. It is characterized by.
According to such a method, the piezoelectric element can be sealed.

[Invention 6] An inkjet recording head manufacturing method according to Invention 6 is the inkjet recording head manufacturing method according to Invention 5, wherein the flow path forming film, or the second flow path forming film and the first flow path formation are provided. Etching a film to form a first contact hole reaching the integrated circuit; etching the protective film to form a second contact hole reaching the piezoelectric element; and on one surface of the substrate Forming a conductive material and filling the first contact hole and the second contact hole; and etching the conductive material to form a wiring for electrically connecting the integrated circuit and the piezoelectric element; And a process.
According to such a method, for example, a driver circuit for driving an ink jet recording head can be disposed as an integrated circuit on one surface of the substrate.

[Invention 7, 8] The ink jet recording head of Invention 7 includes a reservoir that receives an external supply of ink liquid, a pressure generation chamber that communicates with the reservoir, and a nozzle opening that communicates with the pressure generation chamber. An ink jet recording head comprising a substrate on which an integrated circuit and the reservoir are formed, and a flow path forming film provided on one surface side of the substrate, wherein the pressure generating chamber and the nozzle opening are formed And a vibration film provided on the flow path forming film and covering the pressure generating chamber, and a piezoelectric element provided on the vibration film.
An ink jet recording head according to an eighth aspect of the invention is the ink jet recording head according to the seventh aspect, wherein the ink jet recording head discharges the ink liquid supplied to the reservoir from the nozzle opening due to a pressure change in the pressure generating chamber. It is characterized by this.
According to the ink jet recording heads of the seventh and eighth aspects, it is possible to provide an ink jet recording head in which the substrates are not bonded to each other and the nozzle opening is not blocked by the adhesive.

[Invention 9] An ink jet recording apparatus according to an invention 9 includes the ink jet recording head described in the invention 7 or the invention 8.
With such a configuration, it is possible to provide an ink jet recording head in which the substrates are not bonded to each other and the nozzle opening is not blocked by the adhesive. Since such an ink jet recording head can be manufactured at a low cost and with a high yield, it can contribute to the cost reduction of the ink jet recording apparatus.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that, in each drawing described below, parts having the same configuration are denoted by the same reference numerals, and redundant description thereof is omitted.
1A and 1B are diagrams showing a configuration example of an ink jet recording head 100 according to an embodiment of the present invention, in which FIG. 1A is a plan view, and FIG. 1B is FIG. It is sectional drawing when cut | disconnecting by 1 line | wire. As shown in FIGS. 1A and 1B, the ink jet recording head 100 includes, for example, a substrate 1, a flow path forming film 10, a vibration film 30, and a piezoelectric element (that is, a piezoelectric element) 50. Prepare.

  The substrate 1 is, for example, a bulk silicon substrate having a plane orientation (100). A driver circuit 3 for driving the piezoelectric element 50 is integrally formed on the surface of the substrate 1 (that is, the upper surface in FIG. 1B). The substrate 1 has through holes formed so that the diameter gradually decreases from the back surface (that is, the lower surface in FIG. 1B) to the front surface. This through hole is a reservoir 5 that receives the supply of ink liquid from the outside. The volume of the reservoir 5 is sufficiently larger than the volume of all the pressure generation chambers 20 described later. Further, a passivation film 7 for protecting the driver circuit 3 is formed on the surface of the substrate 1.

  The flow path forming film 10 is formed on the surface side of the substrate 1. The flow path forming film 10 has, for example, a laminated structure, and includes a first flow path forming film 11 of the first layer and a second flow path forming film 12 of the second layer as viewed from the substrate 1 side. In the flow path forming film 10 having such a configuration, a plurality of individually divided ink flow paths are formed. Here, the ink flow path is a path through which ink liquid flows, and includes an ink communication path 19, a pressure generation chamber 20, a nozzle communication path 21, and a nozzle opening 22. As shown in FIG. 1B, the ink communication path 19 is a flow path that connects the reservoir 5 and the pressure generation chamber 20 so that the ink liquid flows between them, and the nozzle communication path 21 is the pressure generation chamber 20. And the nozzle opening 22 are flow paths that allow ink liquid to flow between them. The volume of the pressure generating chamber 20 that applies pressure to the ink liquid and the size of the nozzle opening 22 are optimized in accordance with the discharge amount of the ink liquid, the discharge speed, the discharge frequency, and the like.

The flow path forming film 10 and the passivation film 7 therebelow are formed with first contact holes 64 having a pad electrode or the like formed on the surface (ie, active surface) of the driver circuit 3 as a bottom surface. Further, the vibration film 30 is formed on the flow path forming film 10. The vibration film 30 is an elastic film and is formed on the flow path forming film 10 to cover the pressure generation chamber 20.
The piezoelectric element 50 is formed directly above the pressure generation chamber 20 with the vibration film 30 interposed therebetween. As shown in FIG. 1B, the piezoelectric element 50 includes a lower electrode 51, a piezoelectric body 52 formed on the lower electrode 51, and an upper electrode 53 formed on the piezoelectric body 52. The lower electrode 51 is, for example, a common electrode that covers a plurality of piezoelectric elements 50. The piezoelectric body 52 is a dielectric that expands, contracts, or is distorted when a voltage is applied, and is, for example, lead zirconate titanate (PZT). Further, unlike the lower electrode 51, the upper electrode 53 is not a common electrode, but is an individual electrode corresponding 1: 1 with each piezoelectric body. The piezoelectric element 50 having such a configuration is provided directly above each pressure generation chamber 20.

  A protective film 60 is formed on the surface side of the substrate 1 so as to cover the piezoelectric element 50. A second contact hole 65 with the upper electrode 53 as the bottom surface is formed in the protective film 60. A wiring 67 is formed so as to embed the second contact hole 65 and the first contact hole 64 formed in the flow path forming film 10 and the passivation film 7. Through the wiring 67, the upper electrode 53 of each piezoelectric element 50 is connected to the driver circuit 3, respectively. Further, the lower electrode 51 of the piezoelectric element 50 is drawn on the protective film 60 by the wiring 68.

  The ink jet recording head 100 configured as described above takes ink liquid from an external ink supply means (not shown) into the reservoir 5 and, as indicated by an arrow in the figure, the ink reaches from the reservoir 5 to the nozzle opening 22. Fill with liquid. Then, according to the recording signal from the driver circuit 3, a voltage is applied between the upper electrode 53 and the lower electrode 51 of the piezoelectric element 50 to expand and contract the piezoelectric body 52 or cause distortion. As a result, the vibration film 30 is deformed to increase the pressure in the pressure generating chamber 20, and the ink liquid is discharged from the nozzle opening 22.

Next, a method for manufacturing the ink jet recording head 100 will be described. 2 to 8 are views showing a method of manufacturing the ink jet recording head 100 according to the embodiment of the present invention, in which (a) of each figure is a plan view, and (b) of each figure is (a) X. It is sectional drawing when cut | disconnecting by -X 'line.
2A and 2B, first, a driver circuit 3 for driving the piezoelectric element 50 is formed on the surface side of the substrate 1. The driver circuit 3 is formed by a semiconductor process. Note that the wiring formed inside the driver circuit 3 (for example, including the wiring connecting the transistors and the pad electrode which is the uppermost layer wiring) is not a low melting point metal such as aluminum (Al), for example, W, It is preferable to form with a high melting point metal such as WSi ₂ , Ti or TiSi ₂ . This is because, for example, heat treatment at about 700 ° C. is performed in the subsequent piezoelectric film forming step. The wiring formed inside the driver circuit 3 is made of, for example, a metal having a melting point of 1000 ° C. or higher, so that even when heat treatment at about 700 ° C. is performed in a later process, disconnection due to heat, etc. It is possible to prevent the occurrence of defects.

Next, a passivation film 7 is formed on the surface of the substrate 1 so as to cover the driver circuit 3. The passivation film 7 is, for example, a SiO ₂ film or a silicon nitride (Si ₃ N ₄ ) film, and the formation thereof is performed by, for example, CVD (Chemical Vapor Deposition).
Next, as shown in FIGS. 3A and 3B, a first flow path forming film 11 is formed on the passivation film 7. The thickness of the first flow path forming film 11 is, for example, 10 to 100 μm, and the formation is performed by, for example, CVD. Then, the first flow path forming film 11 is partially etched by photolithography and etching techniques, for example, a region that becomes an ink communication path 19 (see FIG. 1) and a nozzle communication path 21 (see FIG. 1). ) And the region to be the nozzle opening 22 (see FIG. 1), the first groove portion 13 is formed respectively.

  Next, the first groove 13 is filled with the first sacrificial film 14. Here, for example, the first sacrificial film 14 is formed on the entire surface of the substrate 1 to fill the first groove 13. The thickness of the first sacrificial film 14 is, for example, substantially the same as the depth of the first groove 13 or a thickness greater than that. Next, the first sacrificial film 14 is planarized by, for example, CMP (Chemical Mechanical Polish), and the first sacrificial film 14 formed in a portion other than the first groove 13 is removed. As a result, the first sacrificial film 14 can be left only inside the first groove 13.

  Next, as shown in FIGS. 4A and 4B, the second flow path forming film 12 is formed on the first flow path forming film 11 and the first sacrificial film 14. The thickness of the second flow path forming film 12 is, for example, 10 to 100 μm, and the formation is performed by, for example, CVD. Then, the second flow path forming film 12 is partially etched by photolithography and etching techniques, for example, a region that becomes the pressure generation chamber 20 (see FIG. 1) and a nozzle opening 22 (see FIG. 1). The second groove 15 is formed in each of the regions to be). Here, the second groove portion 15 is formed so as to be connected to the first groove portion 13. That is, the second groove portion 15 is formed so that the end portion of the second groove portion 15 overlaps the end portion of the first groove portion 13. Thereby, the continuous groove part which consists of the 1st groove part 13 and the 2nd groove part 15 is comprised.

  Next, as shown in FIGS. 4A and 4B, the second groove 15 is filled with the second sacrificial film 16. Here, for example, the second sacrificial film 16 is formed on the entire surface of the substrate 1 to fill the second groove 15. The thickness of the second sacrificial film 16 is, for example, substantially the same as the depth of the second groove 15 or a thickness greater than that. Next, the second sacrificial film 16 is planarized by, for example, CMP, and the second sacrificial film 16 formed in a portion other than the second groove portion 15 is removed. As a result, the second sacrificial film 16 can be left only in the second groove portion 15.

Here, the first and second sacrificial films (hereinafter also simply referred to as sacrificial films) 14 and 16 are removed after the reservoir 5 (see FIG. 1) is formed. Therefore, the sacrificial films 14 and 16 are films having high etching selectivity with respect to the first flow path forming film 11 and the second flow path forming film 12 (that is, the flow path forming film 10), that is, a predetermined film. It is preferable to use a film that is more easily etched than the flow path forming film 10 under etching conditions.
For example, when the flow path forming film 10 is a SiO ₂ film, a-Si films can be used for the sacrificial films 14 and 16. When the flow path forming film 10 is an a-Si film, SiO ₂ films can be used for the sacrificial films 14 and 16. Further, when the flow path forming film 10 is a Poly-Si film, a SiO ₂ film or a SiGe film can be used as the sacrificial films 14 and 16. The SiO ₂ film as the sacrificial film may be a PSG (Phospho Silicate Glass) film.

  The formation method of the sacrificial films 14 and 16 is not limited to the above-described method (that is, a combination of a film formation process by CVD and a planarization process by CMP). For example, by using a so-called gas deposition method or a method called a jet molding method in which ultrafine particles of 1 μm or less collide with the substrate 1 at a high speed by a gas pressure such as helium (He), the sacrificial film 14, 16 may be formed. According to such a method, the sacrificial films 14 and 16 can be filled in the first groove portion 13 and the second groove portion 15 without going through a planarization step by CMP.

Next, as shown in FIGS. 5A and 5B, the vibration film 30 is formed on the second flow path forming film 12 and the second sacrificial film 16. The vibration film 30 is an elastic film as described above, and is made of, for example, a SiO ₂ film, zirconium oxide (ZrO ₂ ), or a film in which these are laminated, and has a thickness of, for example, 1 to 2 μm. When ZrO ₂ is used for the vibration film 30, for example, it is formed by performing sputtering film formation (reactive sputtering film formation) of zirconium (Zr) with plasma containing O ₂ . The material of the vibration film 30 is not limited to the above type, but a material that is not etched or hardly etched in the process of forming the reservoir 5 (see FIG. 1) and the process of removing the sacrificial films 14 and 16 is used. preferable.

  Next, as shown in FIGS. 5A and 5B, the piezoelectric element 50 is formed on the vibration film 30 corresponding to each pressure generation chamber 20. Here, for example, the lower electrode film is formed on the vibration film 30 by a sputtering method. As a material of the lower electrode film, platinum (Pt), iridium (Ir), or the like is preferable. The reason is that a piezoelectric film described later formed by sputtering or sol-gel method needs to be crystallized by baking at a temperature of about 600 to 1000 ° C. in an air atmosphere or an oxygen atmosphere after the film formation. Because. For the material of the lower electrode film, it is necessary to select and use a material that can maintain conductivity under such high temperature and oxidizing atmosphere. In particular, when lead zirconate titanate (PZT) is used as the piezoelectric film, it is desirable to select and use a material that exhibits little change in conductivity due to diffusion of lead oxide. Pt, Ir, etc. are suitable as materials that satisfy such conditions. Next, the lower electrode film is partially etched by photolithography and etching techniques to form the lower electrode 51 having a shape as a common electrode. Then, a piezoelectric film is formed. Here, for example, a so-called sol in which a metal organic substance is dissolved and dispersed in a catalyst is applied, dried and gelled, and further sintered at a high temperature (that is, a sol-gel method) to form a piezoelectric film. As the material of the piezoelectric film, a PZT material is suitable, and the sintering temperature in that case is, for example, about 700 ° C. The method for forming the piezoelectric film is not limited to the sol-gel method, and may be formed by a spin coating method such as a sputtering method or a MOD method (organic metal thermal coating decomposition method). Alternatively, the PZT precursor film may be formed by a sol-gel method, a sputtering method, a MOD method, or the like, and then formed by a method of crystal growth at a low temperature by a high-pressure treatment method in an alkaline aqueous solution. The thickness of the piezoelectric film formed by such a method is, for example, 0.2 to 5 μm.

Next, an upper electrode film is formed. The upper electrode film only needs to be a highly conductive material, and many metals such as Al, gold (Au), nickel (Ni), and Pt, conductive oxides, and the like can be used. Next, the upper electrode film and the piezoelectric film are sequentially partially etched by photolithography and etching techniques to form the upper electrode 53 and the piezoelectric body 52 having a predetermined shape. Thereby, the piezoelectric element 50 including the lower electrode 51, the piezoelectric body 52, and the upper electrode 53 is completed on the vibration film 30.
In the present embodiment, the lower electrode 51 is a common electrode of the piezoelectric element 50 and the upper electrode 53 is an individual electrode of the piezoelectric element 50. However, this may be reversed for the convenience of the driver circuit 3 and wiring. That is, the lower electrode 51 may be an individual electrode and the upper electrode 53 may be a common electrode.

Next, as shown in FIGS. 6A and 6B, a protective film 60 is formed on the entire surface of the vibration film 30 on which the piezoelectric element 50 is formed. The protective film 60 is, for example, alumina (Al ₂ O ₃ ), and is formed by, for example, sputtering, ALD (Atomic Layer Deposition), or MOCVD (Metal Organic CVD). Next, the protective film 60, the vibration film 30, and the flow path forming film 10 are sequentially partially etched by photolithography and etching techniques to form the first contact hole 64. Further, the second contact hole 65 is formed on the upper electrode 53 by the same method before, after or in parallel with the formation of the first contact hole 64.

Next, a conductive film is formed on the entire surface of the substrate 1 to fill the first contact hole 64 and the second contact hole 65. Then, the conductive film is partially etched by photolithography and etching techniques. As a result, as shown in FIGS. 7A and 7B, the wiring 67 that electrically connects the upper electrode 53 of each piezoelectric element 50 and the driver circuit 3 respectively, and the lower electrode 51 that is a common electrode. The wiring 68 is formed on the protective film 60.
Next, as shown in FIGS. 8A and 8B, the reservoir 5 is formed by partially etching the substrate 1 from the back side by photolithography and etching techniques. Here, for example, the substrate 1 is wet-etched using a potassium hydroxide (KOH) aqueous solution. By anisotropic wet etching using KOH, the reservoir 5 is formed so that its diameter gradually decreases, and the (111) plane is exposed on the side surface.

In addition, formation of the reservoir | reserver 5 is not limited to wet etching, For example, you may carry out by dry etching. In this embodiment, the reservoir 5 is formed after the piezoelectric element 50 is formed. However, the present invention is not limited to this, and the reservoir 5 may be formed by any process.
Next, the passivation film 7 exposed on the bottom surface of the reservoir 5 is removed by etching. For example, when the passivation film 7 is an SiO ₂ film, the passivation film 7 is removed by wet etching or dry etching using a hydrofluoric acid (HF) solution. When the passivation film 7 is a Si ₃ N ₄ film, the passivation film 7 is removed by wet etching or dry etching using a hot phosphoric acid solution. As a result, the first sacrificial film 14 is exposed from the bottom surface of the reservoir 5.

Next, the first sacrificial film 14 and the second sacrificial film 16 are etched through the reservoir 5. Thereby, the first sacrificial film 14 and the second sacrificial film 16 are completely removed, and a space surrounded by the flow path forming film 10 and the vibration film 30, that is, an ink flow path is formed. Etching of the sacrificial films 14 and 16 may be performed by either dry etching or wet etching. Here, an etching gas in which the etching speed of the sacrificial films 14 and 16 is higher than the etching speed of the flow path forming film 10. Alternatively, the sacrificial films 14 and 16 are etched using an etching solution. For example, when the flow path forming film 10 is a SiO ₂ film and the sacrificial films 14 and 16 are a-Si films, xenon fluoride (XeF ₂ ) gas can be used as an etching gas.

  When the flow path forming film 10 is an a-Si film or a Poly-Si film and the sacrificial films 14 and 16 are PSG films, an HF solution can be used as an etching solution. By selecting the etching conditions in this way, it is possible to selectively etch and remove the sacrificial films 14 and 16 while suppressing the etching of the flow path forming film 10. Thereafter, the vibration film 30 is partially etched by photolithography and etching techniques to form the nozzle openings 22. Through the steps as described above, the ink jet recording head 100 shown in FIGS. 1A and 1B is completed.

  As described above, according to the embodiment of the present invention, an ink jet recording head is manufactured by performing a semiconductor process (that is, a film forming process, a photolithography process, an etching process, etc.) on one substrate 1. be able to. Compared to the conventional example, since it is not necessary to bond a plurality of substrates, the process can be simplified and the cost can be reduced. Moreover, since the adhesive for bonding is unnecessary, there is no possibility that the nozzle opening 22 is blocked by the adhesive. For this reason, the ink jet recording head can be manufactured at a low cost and with a high yield. In addition, by mounting such an ink jet recording head on an ink jet recording apparatus, it is possible to contribute to the cost reduction of the ink jet recording apparatus.

  In this embodiment, the surface of the substrate 1 corresponds to “one surface” of the present invention, the back surface of the substrate 1 corresponds to “the other surface” of the present invention, and the driver circuit 3 corresponds to “an integrated circuit” of the present invention. It corresponds to. The ink communication path 19 corresponds to the “first communication path” of the present invention, and the nozzle communication path 21 corresponds to the “second communication path” of the present invention. Further, the first sacrificial film 14 and the second sacrificial film 16 correspond to the “sacrificial film” of the present invention, and the first groove portion 13 and the second groove portion 15 correspond to the “groove portion” of the present invention.

In the above embodiment, the case where the flow path forming film 10 has a two-layer structure (that is, the first flow path forming film 11 and the second flow path forming film 12) has been described. It is not limited to this. For example, as shown in FIG. 9, the flow path forming film 10 may have a single layer structure. Even in such a case, the ink flow path can be formed in the flow path forming film 10 by the same method as in the above embodiment. Further, when the flow path forming film 10 has a single-layer structure, there is a possibility that the nozzle opening 22 is distorted due to the expansion and contraction of the piezoelectric element 50. Therefore, as shown in FIG. 9, when the flow path forming film 10 has a single layer structure, an adapter 22 a may be provided on the opening side of the nozzle opening 22. The adapter 22a is made of, for example, a SiO ₂ film or a Si ₃ N ₄ film. Thereby, since the nozzle opening 22 is thickened, distortion is less likely to occur and the direction in which the ink liquid is ejected can be stabilized.

1 is a diagram illustrating a configuration example of an ink jet recording head 100 according to an embodiment. FIG. 2 is a diagram illustrating a method for manufacturing an ink jet recording head 100 (part 1). FIG. 2 is a diagram illustrating a method for manufacturing the ink jet recording head 100 (part 2). FIG. 3 is a diagram illustrating a method for manufacturing the ink jet recording head 100 (No. 3). FIG. 4 illustrates a method for manufacturing the ink jet recording head 100 (No. 4). FIG. 5 illustrates a method for manufacturing the ink jet recording head 100 (part 5). FIG. 6 illustrates a method for manufacturing the ink jet recording head 100 (No. 6). FIG. 7 illustrates a method for manufacturing the ink jet recording head 100 (No. 7). FIG. 4 is a diagram illustrating another configuration example of the ink jet recording head 100. The figure which shows a prior art example.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Board | substrate, 3 Driver circuit, 5 Reservoir, 7 Passivation film | membrane, 10 Flow path formation film, 11 1st flow path formation film, 12 2nd flow path formation film, 13 1st groove part, 14 1st sacrificial film, 15 2nd Groove, 16 second sacrificial film, 19 ink communicating portion, 20 pressure generating chamber, 21 nozzle communicating portion, 22 nozzle opening, 30 vibrating membrane, 50 piezoelectric element, 51 lower electrode, 52 piezoelectric body, 53 upper electrode, 60 protection Film, 64 first contact hole, 65 second contact hole, 67, 68 wiring

Claims (1)

A reservoir that receives supply of ink liquid from the outside, a pressure generation chamber that communicates with the reservoir,
A nozzle opening communicating with the pressure generating chamber, and an ink jet recording head manufacturing method comprising:
Forming a first flow path forming film on one surface side of a substrate having an integrated circuit containing a refractory metal having a melting point of 1000 ° C. or higher in the wiring material;
The first flow path forming film in a region serving as a first communication path connecting the pressure generation chamber and the reservoir, and the first in a region serving as a second communication path connecting the pressure generation chamber and the nozzle opening. Forming a first groove in each flow path forming film;
Filling the first trench with a first sacrificial film;
Planarizing the filled first sacrificial film; and
Forming a second flow path forming film on the first flow path forming film and the planarized first sacrificial film;
The second flow path forming film in the region serving as the first communication path connecting the pressure generation chamber and the reservoir, and the second in the region serving as the second communication path connecting the pressure generation chamber and the nozzle opening. A second groove portion is formed by the second flow path forming film and the second flow path forming film in a region extending in parallel with the surface of the substrate, connecting the region serving as the first communication path and the region serving as the second communication path. And a process of
Filling the second trench with a second sacrificial film;
Forming a vibration film on the second sacrificial film and the second flow path forming film;
Forming a piezoelectric element on the vibrating membrane;
Forming an insulating protective film on the piezoelectric element;
Etching the substrate from the other surface side until the first sacrificial film is exposed to form the reservoir;
Removing the first sacrificial film and the second sacrificial film through the reservoir to form a groove portion including the first groove portion and the second groove portion communicating with at least two locations of the first groove portion; When,
Forming the nozzle opening in the second flow path forming film;
Etching the second flow path forming film and the first flow path forming film to form a first contact hole reaching the integrated circuit;
Etching the protective film to form a second contact hole reaching the piezoelectric element;
Forming a conductive material on one surface of the substrate to fill the first contact hole and the second contact hole;
Etching the conductive material to form a wiring that electrically connects the integrated circuit and the piezoelectric element, and
The step of forming the nozzle opening includes
Forming the second groove in the second flow path forming film in a region to be the nozzle opening;
Filling the second trench with the second sacrificial film;
And a step of etching and removing the second sacrificial film through the reservoir after the step of forming the reservoir.

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